Fluorescent lamp starter



Jan. 1e, 1945.

c. H.V HoDGglNs irl-AL.,

FLUORESCENT LAMP STARTER Filed Magen J2. 194:5

relay opera reference tothe the socket terminals 8 and l high ohmic electrical resist- 4Patented Jan. 16, 1945 2,367,645 FLUORESCENT LAMP STARTER- Charles H. Hodgkins,

merstrom, Bridgeport, Conn., assgnors to T Bryant Electric Company, corporation o Connecticut application March l2. 19:13, Serial No.. 478,894

Fairfield, and Oscar Hamhe Bridgeport, Conn., a

8 Claims (Cl. ZMS-m2) The present invention relates to starting relays for :fluorescent lamps and particularly to a there mal relay which automatically operates to start such lamps, and ii for any reason the lamp fails to start alter a predetermined period of time, 'the the source of supply and is automatically reset upon replacement oi the iailed lamp.

The primary object oi the present invention le to provide a relay oi this character which is sim ole and economical to manufacture.

Anci-,her object oi the invention is the provision oi an economical thermal relay for the start ing oi fluorescent lamps wherein separation oi the contacts occurs with a positive and rapid break, thus eliminating arcing loetvve the cone tacto.

Still further objects of the present invention will become obvious to those skilled in the art ley accompanying drawing wherein:

Fig. i is a sectional view of the starting relay unit oi the present invention and showing a iront elevational view of the relay itself.

Fig. 2 is a fragmentary sectional view ofthe relay o Fig. l taken at 90 to the latter and showing the normal open position of the relay prior ,to its operating.

Fig. 3 is a sectional view taken on the line III- Ill of Fig. l. f

Fig. 4 is a sectional `View taken on the line iV-IV of Fig. 1 and showing the closed circuit position of the relay.

Fig. 5 is a sectional View identical to Fig. 4 but showing the position of the relay in t locke out position thereof which it assumes when a fluorescent lamp becomes defective. l

es to disconnect the tailed laine lll n as hereinafter more fully explained.

ance heater il eyelets i3 and is electrically connected to the lli icy rod-like conductors lo and it which also serve as a support ior the heater so as to dispose the latter inspaced relation to the lease il. il. lcraclset il@ (Fig. 2) extends oui'n 'wardly from the oase member lll with one end thereof electrically connected to the eyelet lll. which loraclret iorrns a support for one oi a ll-shaned himetallic element i?. which thus nare tially surrounds the high ohmc resistance heater il.

il. second himetalllc element iree end of the blrnetallic element 22 and is dit posed in substantially parallel spaced relation above the latter throughout substantially the en@ tire-longitudinal axis thereof. As will he noted in the several iigures, the bimetallic element 23 is or greater length than the loimetallic element it and a contact terminal 24 is amxed to the extend ing free end of the over-lapping bimetallic element it. This contact is normally disposed in spaced relation to a stationary contact 25 spaced irom the hase and a low resistance heater element 2t is disposed in juxtaposition to the stationary. contact 25 being electrically connected to the latter and to the eyelet I3. in addition, a bracket 21 is secured at one end to the base I2 and extends therefrom in an angular direction so as'to form a stop 28 disposed in the path of movement of the joined ends of the bimetallic elements 22 and 23 Fig. 6,

By reference now more particularly to a iluorescent lamp 30 is therein shown provided Fig. 6 is a schematic diagram or the circuit for` starting a fluorescent lamp and utilizing the ther mal relay of the present invention. Referring now to the drawing in detall,.the starting relay of the present invention is shown generally at 5 in the several figures and is housed within 'a metallic or plastic casing 6 together with a rado-frequerley-suppressing condenser' l, both of which are connected in electrical parallel to a pair of socket terminals 8 and 9 adapted to engage a socket andwhich are secured to an insulating closure member I0. n

The relay itself comprises a base I2 of suitable insulating material such as liber, a, phenolic condensation product, hard rubber or the like, 'and as shown '1n Fig. -1 the base lis provided with a pair of eyelets I3 and I4 which are connected to 9 by conductors I 5 and I6, respectively. A

with a pair of lamentary electrodes 32 and 33. lOne end of the lamentary electrode 32 is connected through an-inductance 34 to one side of the source of supply L--I of the customary domestic potentialof 115 volts, and, similarly,VV one end of the lamentary electrode 33 is connected socket terminals through a hand switch 3'5 to the opposite side of the supply sourcek L2. The remaining ends oi the fllamentary lamp electrodes 32 and 33 are connected together through the thermal relay device 5.

It will be noted that the high ohmic resistance heater element I1 being connected acrossy the 8 and 9 will accordingly receive full line voltage upon closure of 35. The heat thus generated by the heater is transmitted by radiation to the adjacent bime# tallic element 22,. Inasmuch as one end of this latter bimetallic element is anchored to the bracket 20, '1t remains fixed, with the .result that the free end thereof detlects away from the heater element and base I2. Since the bimetalilc eleit is secured to the l moves away stationary contact Fig. 4.

The engagement with 25 in the manner shown in of the movable contact. 24 the stationary Contact 25 y heater element I1 accordingly stops the generation of heat, with the result that the shorter 'bimetallic element 22 begins to cool and return to its normal position as shown in Fig. 2.

However, the time during which the contacts 2l and 25 remain in engagement with each other inductance 34, thus initiating a discharge between the preheated filamentary lamp electrodes l32 and.

During operation of the lamp, voltage is impressed across the operation or the relay 5,-the cycle of operation the relay will lock- For example, upon initial high ohmic resistance heater I1, resulting' in cy. clic operation of the relay for a predetermined period of time.

est

the contacts.

In addition, the relay operates Ibecoming defective to 1ocl -out eliminating repetitions upon the lamp the same, thus tmentioned element throughout the entire lungiof said second mentioned bimetallic element and cause deflection or the latter in an opposite direction with positive and rapid separation oi said movable contact from. said stationary Contact.

3. ifi thermal charge lamps comprising a base, an electric resistance heater supported by said base, a sub stantially U-shaped bimetallic element supported at one end from said base and partially surrounding said heater and operable to deflect away from said base under heat from said heater, a second bimetallic element oi greater length than Isaid first mentioned bimetallic element to increase the distance of deflection thereof attached to the iree end of the latter and normally disposedin substantially parallel spaced relation above said first-mentioned bimetallic element throughout the entire longitudinal axis thereoi, a stationary contact supported by said base, a contact carried by the tree end o said second mentioned bimetallic element normally spaced irom said stationary contact and movable into engagement therewith solely by deflection of said first mentioned bimetallic element away heat from said heater to short-circuit the latter, and a low resistance heater in juxtaposition to said stationary contact and operable upon en gagement oi said contacts with attendant shortcircuit o said first mentioned heater and cooling oi said first mentioned bimetallic element to heat the extending end of said second mentioned bimetallic element and cause deflection ci the latter toward said base with a positive and rapid separation of said movable contact from said sta= tionary contact.

d. A thermal relay for gaseous electric discharge lamps comprising an electric heater, a bi metallic element secured at one end and partially its free end deflectsurrounding said heater with able away from said heater under heat from the latter; a second birnetallic element attached'to the `free end of said first mentioned bimetallic element and normally disposed in substantially parallel spaced relation above the latter throughout the entire longitudinal axisr thereof, a stationary contact, a contact carried by the iree end of said second mentioned bimetallic element vand normally movable into engagement with said stantiary contact solely by deflection of said first mentioned bimetallic element under normal heat from said heater to short-circuit' the latter, and means disposed in the path ci defiection'o said first mentioned bimetallic element to limit move ment thereof upon undue heating by said heater iollowing iailure ol the discharge lamplto start after cyclic operation oi said relay lor a prede termined periodoi time and ior causing the ree sultant heat to deect said second mentioned bic metallic element. and maintain said contacts m a separated'position until replacement or the dis charge lamp..

5. A thermal relay or. gaseous electric dise' charge lamps comprising an-electric.-heaterD a bimetallic element securedv at one end and pars tially surrounding said heater with its free end deflectable away from said heater under heat from the latter, a second bimetallic element attached to the free end of said first mentioned bimetallic element and normally disposed in substantially parallel spaced relation above the latter throughout the entire longitudinal axis thereof, a stationary Contact; acontact carried by the free end of said second mentioned bimetal lic element and normally movable into engagerelay for gaseous electric disfrom said base under ment with said stationary contact solely by clea flection of said 'first mentioned bimetallic ele@ ment under normal heat from said heater tc short-circuit the latter, and a stop disposed inthe path of deilection oi said first mentioned bimetai lic element to limit deflection thereo upon undue heating by said heater following failure of the discharge lamp to start after cyclic operation ci said relay for a predetermined period oi time and for causing the resultant heat to denect said second mentioned bimetallic element and mainu tain said contacts in a separated. position until replacement ci the discharge lamp.

6.a thermal relay lor gaseous electric disn charge, lamps comprising an electric heater, a bimetallic element secured at one end and tially surrounding said heater with its free end deiiectable away' from the anchoredend when heated by said heater, asecond bimetallic elem ment of greater length than said first mentioned bimetallic element attached to the freeend oi thew latter and normally disposed in substantially parallel spaced relation above said first menn tioned bimetallic element throughout the entire longitudinal axis thereof, a stationary contact, contact carried by the free end of said second mentioned bimetallic element and normally mov able into engagement with said stationary cori= tact solely by deection o said first mentioned bimetallic element under normalheat from Said heater to short-circuit the latter, and a stop posi1 tioned to be engaged by the joined ends oi said bimetallic elements to limit erleetion tliereoupon undue heating of said heater following failure or the discharge lamp to start after cyclic operation of said relay for a predetermined period of time and for causing the resultant heat to deflect the extending end of said second mentioned bimetallic element in a direction opposite to its movement under the influence of said irst mentioned bimetallic element to maintain said con= tacts in a separated position until replacement of the discharge lamp.

71. fl thermal relay for gaseous electric dis charge lamps comprising an electric resistance heater, a bimetallic element secured at one end and ypartially surrounding said heater with its free endldeflectable away Ji'rorn said heater under heat from the latter, a second bimetailic elen ment attached to the free end'oi said first mena tioned bimetallic element and normally disposed in substantially parallel spaced relation above the latter throughout the entire longitudinal axis thereoi,`a stationary contact, a contact carn ried by the free end ci said second mentioned bimetallie element and normally movable into engagement with said stationary contact solely by deflection, or said first mentioned bimetallic element under normal heat from said heater to short-circuit the latter, a low resistance heater adjacent said stationary contact and operable upon engagement ci said contacts with attendant short-circuiting oi said first mentioned heater and cooling oi said first mentioned bimetallic element to heat said second mentioned bimetallic element and cause deflection of the latter with a positive andrapid separation o said movable contact from said stationary contact, and means disposed in the path of deflection of said first mentioned bimetallic element to limit movement thereof upon undue heating by said heater iollowing failure of the discharge lamp to start after cyclic operation of said relay tor a preden termined period of time and for causing the resultant heat to deflect sai; second mentioned 4 ascaciis bimetallic element and maintain said contacts con in a separated position until replacement of the contacts with attendant short-circuiting of said discharge lamp. first mentioned heater and cooling of said first and partially surrounding said 4heater with its opposite direction with positive and rapid sepafree end defiectable away from said heater when ration of said movable contact from said staiieated by the latter, a second bimetallic element tionary contact, and a stop engag'eable by the of greater length than said first mentioned bilo joined ends of said bimetallic elements to limit metallic element attached to the free end of the deflection thereof upon undue heating of said latter and normally disposed in substantially heater following failure of the discharge lamp longitudinal axis thereof, a stationary contact, a is the resultant heat to deiiect the extending end mentioned bimetallic element and normally movdirection opposite to its movement 4under the inable into engagement with said stationary coni'iuence of said first mentioned bimetallio element tact solely by deflection of said rst mentioned to maintain said contacts in a separated posibimetallc element under normal heat from said 2U tion until replacement of the discharge lamp. heater to short-circuit the latter, a low resst- CHARLES H. HO'DGKINS. ance heater in juxtaposition to said stationary OSCAR HAMMERSTROM. 

